What is the management of anaphylaxis?

From the Guidelines

The management of anaphylaxis requires immediate administration of epinephrine (adrenaline) as the first-line treatment, with a dose of 0.01 mg/kg up to 0.5 mg for adults and 0.3 mg for children, administered intramuscularly into the mid-outer thigh, which can be repeated every 5-15 minutes if symptoms persist, as recommended by the most recent and highest quality study 1. For adults, administer 0.3-0.5 mg of 1:1000 (1 mg/mL) epinephrine intramuscularly into the mid-outer thigh; for children, the dose is 0.01 mg/kg up to 0.3 mg. Some key points to consider in the management of anaphylaxis include:

• After epinephrine administration, place the patient in a supine position with legs elevated unless respiratory distress is present, as suggested by 1 and 1.
• Remove the trigger if possible.
• Provide supplemental oxygen at 8-10 L/min via face mask if respiratory symptoms are present, as recommended by 1.
• Establish IV access for fluid resuscitation with normal saline (1-2 L for adults, 20 mL/kg for children) to counter hypotension, as suggested by 1. Some second-line medications that can be used in the management of anaphylaxis include:
• Antihistamines (diphenhydramine 25-50 mg IV/IM for adults) to relieve urticaria and pruritus.
• Corticosteroids (methylprednisolone 1-2 mg/kg IV) to prevent biphasic reactions, though these should never delay epinephrine, as recommended by 1 and 1.
• For bronchospasm, consider albuterol via nebulizer, as suggested by 1. It is essential to continuously monitor vital signs and observe patients for 4-8 hours due to the risk of biphasic reactions, with severe cases requiring 24-hour observation, as recommended by 1 and 1. Epinephrine works by causing vasoconstriction, increasing cardiac output, and bronchodilation, directly counteracting the life-threatening effects of anaphylaxis including hypotension and airway compromise, as explained by 1.

From the FDA Drug Label

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action Epinephrine acts on both alpha and beta-adrenergic receptors. 12. 2 Pharmacodynamics Through its action on alpha-adrenergic receptors, epinephrine lessens the vasodilation and increased vascular permeability that occurs during anaphylaxis, which can lead to loss of intravascular fluid volume and hypotension Through its action on beta-adrenergic receptors, epinephrine causes bronchial smooth muscle relaxation and helps alleviate bronchospasm, wheezing and dyspnea that may occur during anaphylaxis Epinephrine also alleviates pruritus, urticaria, and angioedema and may relieve gastrointestinal and genitourinary symptoms associated with anaphylaxis because of its relaxer effects on the smooth muscle of the stomach, intestine, uterus and urinary bladder

The management of anaphylaxis involves the use of epinephrine, which acts on both alpha and beta-adrenergic receptors to alleviate symptoms such as:

• Vasodilation and increased vascular permeability
• Bronchospasm, wheezing, and dyspnea
• Pruritus, urticaria, and angioedema
• Gastrointestinal and genitourinary symptoms Epinephrine is administered parenterally and has a rapid onset and short duration of action 2.

From the Research

Management of Anaphylaxis

The management of anaphylaxis involves prompt recognition and treatment of the condition to prevent morbidity and mortality.

• Anaphylaxis is a systemic allergic reaction that often involves respiratory symptoms and cardiovascular collapse, which are potentially life-threatening if not treated promptly with intramuscular adrenaline 3.
• The first-line treatment for any anaphylaxis episode, regardless of severity, is intramuscular injection of epinephrine into the anterolateral thigh 4, 5, 6.
• Epinephrine is life-saving and the only first-line medication in the management of anaphylaxis, acting rapidly to reverse nearly all symptoms of anaphylaxis and stabilize mast cells 6.

Treatment Approaches

Different treatment approaches have been explored, including:

• Intramuscular injection of epinephrine, which is the standard approved dose and has a long track record for safe and effective use 4, 5, 6.
• Sublingual route of administration of epinephrine, which has been successful in animal studies 5.
• Use of corticosteroids, which appear to reduce the length of hospital stay, but there is no consensus on whether they reduce biphasic anaphylactic reactions 7.

Key Considerations

Key considerations in the management of anaphylaxis include:

• Prompt administration of epinephrine to minimize morbidity and mortality 4, 5, 6.
• Availability and accessibility of epinephrine autoinjectors, which should be affordable, readily available, and easy for patients with allergies to carry and use 3, 6.
• Education and training of patients, caregivers, and healthcare professionals on the use of epinephrine autoinjectors and the recognition of anaphylaxis symptoms 3, 4, 6.